from the District Court of Natrona County The Honorable W.
Thomas Sullins, Judge
Representing Appellant:Office of the State Public Defender:
Diane M. Lozano, State Public Defender; Tina N. Olson, Chief
Appellate Counsel. Patricia L. Bennett, Appellate Counsel.
Argument by Ms. Bennett.
Representing Appellee: Peter K. Michael, Attorney General;
David L. Delicath, Deputy Attorney General; Christyne M.
Martens, Senior Assistant Attorney General; Jesse B. Naiman,
Assistant Attorney General. Argument by Mr. Naiman.
BURKE, C.J., and HILL, DAVIS, FOX, and KAUTZ, JJ.
Donald Young appeals his conviction of driving under the
influence of alcohol. He contends that the district court
erred in permitting the State to introduce expert testimony
involving retrograde extrapolation to prove that Mr.
Young's blood alcohol level was above 0.08% while he was
driving on the night in question. We affirm.
The issue to be resolved, as set forth by the State, is
whether the district court committed plain error when it
allowed the State to introduce retrograde extrapolation
On the evening of August 1, 2014, Lanette Brown and her son,
DY, were visiting her cousin and his children. They were
outside in the yard. At around 10:30 that evening, Mr. Young
drove his vehicle, a red Cadillac, to the cousin's home,
intending to pick up his son. Ms. Brown testified that she
"knew [Mr. Young] was intoxicated because he was kind of
staggering, and he was a little bit belligerent towards my
cousin." She smelled the odor of alcohol on him. He
asked where his son was, even though the boy was standing
nearby. She told Mr. Young that he could not take his son.
Apparently ignoring her, Mr. Young took his son by the arm
and pulled him toward the car. The son also smelled alcohol
on his father's breath, and did not want to get in the
car with him. He pulled away from his father, and ran to his
own home a short distance away. Mr. Young returned to his
car, and started driving it down the street in reverse. He
was driving fast, and his tires were squealing and
screeching, when he struck a parked vehicle. Hearing the
crash, Ms. Brown called 911. She made the call at 10:39 p.m.
By the time police arrived, Mr. Young and his car had left
the scene of the collision. Another team of police went
directly to Mr. Young's residence. They arrived at the
residence at approximately 10:50 p.m. and found Mr. Young
outside his residence. They also observed a Cadillac with
damage that an investigating officer described as
"fresh." When the officers interviewed Mr. Young,
they observed that he smelled of alcohol, had bloodshot eyes,
and slurred his speech. The police subjected him to field
sobriety tests. After concluding the tests, the officers
determined that Mr. Young was intoxicated and arrested him.
At the police station, at sixteen minutes after midnight, Mr.
Young was given a breath test, which indicated his blood
alcohol level was 0.079%. He was charged with driving under
the influence of alcohol, fourth offense, in violation of
Wyo. Stat. Ann. § 31-5-233(b) (LexisNexis 2013). He was
also charged with unlawfully operating a vehicle without a
required ignition interlock device in violation of Wyo. Stat.
Ann. § 31-7-404(a), failure to stop upon colliding with
an unattended vehicle in violation of Wyo. Stat. Ann. §
31-5-1104, and failure to maintain liability coverage in
violation of Wyo. Stat. Ann. § 31-4-103(a).
Prior to trial, Mr. Young filed a motion in limine. According
to the motion, "It is the Defendant's intent to
object at trial, if and when, the [State] attempts to put on
any and all evidence in reference to the defendant's
consumption of alcohol (without accounting for the time the
defendant was not in the presence of law enforcement or any
other witness)." The motion asserted that this evidence
is irrelevant "without accounting for the
Defendant's actions between the period of time police
responded to a report of a hit and run accident; and, the
time law enforcement made contact with the defendant."
The motion identified the Defendant's blood alcohol
content taken at the Natrona County Detention Center,
testimony from a retrograde extrapolation expert, video from
the police cruiser of the field sobriety tests administered
by the Casper Police Department, and video from the police
cruiser of the Defendant being transported to the Natrona
County Detention Center as examples of evidence that were
included in the motion. After argument, the district court
denied the motion. The court did, however, clarify that the
evidence at issue could be challenged during trial and that
the court would be "inclined to give the Defense a right
to voir dire if there needs to be clarification with
testimony under oath to support the concerns that have been
expressed by the Defense."
During trial, the State called Moss Kent, a forensic
toxicologist, to testify. Mr. Kent testified that based on
his retrograde extrapolation calculations, Mr. Young's
blood alcohol concentration at 10:39 p.m. on the night in
question would have been between 0.095% and 0.124%, above the
legal limit of 0.08% set out in Wyo. Stat. Ann. §
31-5-233(b)(i). He explained that his opinion was based on
the undisputed fact that the breathalyzer test Mr. Young took
97 minutes after the accident showed a blood alcohol level of
0.079%. He testified that a person eliminates alcohol from
his body at a steady, constant rate. Accordingly, if a
person's blood alcohol level is known at a certain point
in time, his blood alcohol level at an earlier time may be
determined by calculating how much alcohol was eliminated
from his body between the two points in time. Mr. Kent also
testified that different people eliminate alcohol at
different rates. Because he did not know Mr. Young's
particular rate of elimination, he used a range of
elimination rates. He calculated that Mr. Young's blood
alcohol level when he was driving his car would have ranged
from 0.095% to 0.124%. His opinion was predicated upon the
assumption that Mr. Young was in the post absorption phase
when the breathalyzer test was given.
When the State sought to admit Mr. Kent's retrograde
extrapolation calculations into evidence, the district court
asked Mr. Young if he had any objection. Mr. Young did not
object. After the State rested, Mr. Young moved for a
judgment of acquittal. The district court granted the motion
as to the charge ...